I agree the 'attaboy' comments are way out of place, but there is also an over the top reaction the other way with the criticism being heaped onto the AirBNB guys in my opinion.

It was technically wrong of them to leverage craigslist by circumventing the community's own "no commercial email" request, and they should get dinged for it.

But in the grand scheme of things, when you are a tiny start up struggling to survive, this is a relatively benign grass roots attempt at marketing which the AirBNB guys even probably regret doing.

Comparing RIAA's scare tactics to this seems a little out of place, but it is right in line with Microsoft's shady attempts at astroturfing.